1. Field of the Invention
This invention relates to the medical treatment of ocular disease. More particularly this invention relates to an electronic apparatus for the application of electrical current to the eye for treating diseases thereof, for example macular degeneration.
2. Description of the Prior Art
Macular degeneration is a debilitating ocular disease having hemorrhagic and exudative variants, both of which are susceptible to safe and efficient treatment by the invention hereof. Treatment typically results in amelioration of the ophthalmoscopic manifestations of the disorder, and substantial restoration of central visual acuity.
It is proposed in Fedorov et al., U.S. Pat. No. 5,147,284, to treat diseases of the optic nerve and retina by the application of a pulsed 3.5 magnetic flux, the magnetic field induction being from 0.1 T to 0.25 T. However the technique is invasive, requiring exposure of the posterior portion of the eyeball and optic nerve and introduction of the inducer into the orbit.
It is proposed to treat glaucoma with the application of transcutaneous electrical stimulation from Liss et al., U.S. Pat. No. 4,614,193. Liss et al. discloses the application of pulsed electrical current at a level less than 4 milliamperes, the pulse trains occurring at 12-20 kHz, amplitude modulated at 8-20 hz, and having a 3:1 duty cycle. Applying this waveform through electrodes positioned on the temple and on the ipsilateral hand, Liss et al. achieved an approximately 28% reduction in intraocular pressure in the treated eye. To the knowledge of the inventors, passage of electrical current through the eye (hereinafter "transocular electrical conduction") has not been used in the art for the treatment of macular degeneration.